Biotechnology for Biofuels最新文献

{"title":"Oxygen competition induces chlorosis in thermoacidophilic methanotroph–microalgae cocultures","authors":"Carlos Cartin-Caballero,&nbsp;Christophe Collet,&nbsp;Daniel Gapes,&nbsp;Peter A. Gostomski,&nbsp;Matthew B. Stott,&nbsp;Carlo R. Carere","doi":"10.1186/s13068-026-02759-1","DOIUrl":"10.1186/s13068-026-02759-1","url":null,"abstract":"<div><p>Methanotroph–microalgae cocultures offer a promising bioprocess platform for methane (CH₄) and carbon dioxide (CO₂) valorisation and have been proposed for sustainable single-cell protein (SCP) production. In coculture, the thermoacidophilic methanotroph <i>Methylacidiphilum</i> sp. RTK17.1 can benefit from oxygen supplied by the extremophilic microalga <i>Galdieria</i> sp. RTK37.1 under low-O₂ conditions, enhancing growth and methane oxidation. However, oxygen availability is a critical factor that can rapidly become limiting and is dependent on the relative abundance of each coculture partner. Here, we investigated how the initial <i>Methylacidiphilum</i>:<i>Galdieria</i> biomass ratio influences coculture dynamics and overall carbon assimilation. At low initial ratios (&lt; 0.18 gDW L⁻¹: gDW L⁻¹), CH₄-fed cocultures achieved 17–28% greater net carbon fixation than CH₄-free controls (<i>p</i> &lt; 0.05), indicating effective methanotroph–microalgae synergy via oxygen exchange. In contrast, ratios ≥ 0.23 led to significant growth inhibition (66–100% reduction, <i>p</i> &lt; 0.001) and reduced net carbon fixation (44–62% reduction, <i>p</i> &lt; 0.001). These cocultures exhibited chlorosis and excreted coproporphyrin III, symptoms that were fully reversible upon oxygen replenishment. Collectively, these findings reveal that <i>Galdieria</i> sp. RTK37.1 requires a minimum oxygen threshold for photosystem pigment biosynthesis, while the high O₂ affinity of <i>Methylacidiphilum</i> sp. RTK17.1 can result in oxygen limitation at elevated methanotroph abundance. Consequently, interactions that are mutually beneficial at low methanotroph densities become inhibitory due to oxygen competition. This work highlights the central role of O₂ partitioning in extremophile cocultures and provides a mechanistic basis for optimising methane-fed photobioreactors relevant to SCP production and carbon valorisation.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"19 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2026-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1186/s13068-026-02759-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147523071","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rhodotorula toruloides for carotenoid production using waste hardwood biomass","authors":"Stefano Bertacchi,&nbsp;Francesca Sabatini,&nbsp;Giovanni Maria Bernardini,&nbsp;Matilde Dameri,&nbsp;Veronica Termopoli,&nbsp;Danilo Porro,&nbsp;Marco Orlandi,&nbsp;Heiko Lange,&nbsp;Paola Branduardi","doi":"10.1186/s13068-026-02749-3","DOIUrl":"10.1186/s13068-026-02749-3","url":null,"abstract":"<div><p>This work explores the potential of underutilized urban pruning residues from hardwood as feedstocks for bioprocesses based on the carotenogenic yeast <i>Rhodotorula toruloides</i>, investigating the correlation between biomass composition and carotenoids production. Enzymatic hydrolysates derived from woods and barks of sessile oak and mulberry tree were used as substrates for microbial fermentation. The results demonstrated superior titers, yields, and productivity for β-carotene and torulene compared to previously reported processes. While mulberry tree bark hydrolysate yielded the highest total sugars (16.4 g/L), sessile oak bark hydrolysate achieved the highest β-carotene production (362.7 mg/L) and yield on dry cell weight (163.4 mg/g) after 30 h of fermentation. Woody biomasses are known to contain significant amounts of extractive inhibitory compounds. Surprisingly, when these extractives were removed to promote growth, a significant drop in carotenoids titers were observed, bringing them in line with published values obtained from biomasses lacking such components. These data suggest that stress-inducing compounds present in the extractive fractions are crucial for promoting high productivity and yield, when compared with the use of biomasses lacking such components. This research highlights the untapped potential of urban woody residues, which thanks to the presence of triggering components can be considered as advantageous feedstock for microbial carotenoids production.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"19 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2026-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1186/s13068-026-02749-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147517585","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microaerobic dark fermentation by purple bacteria as an emerging perspective for biohydrogen production—a review","authors":"S. Krake,&nbsp;G. E. M. Tovar,&nbsp;S. Zibek","doi":"10.1186/s13068-026-02747-5","DOIUrl":"10.1186/s13068-026-02747-5","url":null,"abstract":"<div><p>While in recent years, a lot of research regarding microbial dark fermentation for biohydrogen production has been carried out focusing on improving well-established processes, this review aims to draw attention to the discovery of a new method of process control, i.e., microaerobic dark fermentation in purple non-sulfur bacteria. This new subsegment of research tries to rethink efficiencies of biohydrogen production and substrate conversion based on an increasingly comprehensive understanding of metabolic pathways, particularly in the area of interplay between aerobic and anaerobic metabolism and the control of this state. By combining hydrogen production through dark fermentation and partially activated photofermentation by a partially active nitrogenase (~ 12%), microaerobic fermentation has the potential to increase hydrogen efficiency. At the same time, it allows to maintain advantages of facultative aerobes, such as high-cell densities and growth rates. Studies show that very high yields of up to 8–12 mol H₂ mol⁻¹ substrate should theoretically be possible with this method, but the yields currently realized are still in the range already achieved with dark fermentation (0.2–1.6 mol H₂ mol⁻¹ substrate). This review provides an overview of the relevant bacteria, metabolism, cultivation, and challenges to further increase hydrogen productivity using microaerobic dark fermentation by purple bacteria. In addition, the model microorganism <i>Rhodospirillum rubrum</i> is considered in more detail to gain a deeper understanding of the processes at the metabolic level under microaerobic conditions. The review concludes with a detailed proposal of the challenges and opportunities to create a new, exciting perspective for biotechnological hydrogen production by microaerobic dark fermentation.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"19 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2026-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1186/s13068-026-02747-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147517606","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Temperature-driven metabolic acceleration independent of cell growth enables high-level production of d-ribulose and shinorine in Streptomyces lividans","authors":"Jun Sakurai,&nbsp;Akari Nakahama,&nbsp;Kentaro Nakazawa,&nbsp;Hiroto Uchikura,&nbsp;Yuko Taniguchi,&nbsp;Setsu Kato,&nbsp;Shogo Yamamoto,&nbsp;Yota Tsuge","doi":"10.1186/s13068-026-02758-2","DOIUrl":"10.1186/s13068-026-02758-2","url":null,"abstract":"<div><h3>Background</h3><p>Temperature strongly influences cellular metabolism through its effects on enzyme activity. Although the optimal growth temperature generally reflects the collective temperature dependence of enzymes involved in proliferation, the optimal temperature for metabolite production may differ from that for cell growth. <i>Streptomyces lividans</i> is regarded as a preferred host for heterologous gene expression to produce recombinant proteins and secondary metabolites via the introduction of biosynthetic gene clusters (BGCs). However, its primary metabolism and the effects of temperature on it have not been well studied.</p><h3>Results</h3><p>We found that <i>S. lividans</i> exhibited enhanced glucose consumption at elevated temperature, even under conditions where many cells were non-viable. At 40 °C, the glucose consumption rate increased by 45% compared to 28 °C, the conventional optimal growth temperature, although the colony-forming unit count at 40 °C was less than one-tenth of that at 28 °C. The elevated temperature drastically reduced cell length and increased the proportion of dead cells observed by fluorescence microscopy. Moreover, we, for the first time, observed that <i>S. lividans</i> produced the rare sugar <span>d</span>-ribulose, and its production was strongly enhanced by temperature elevation. At 40 °C, <span>d</span>-ribulose concentration reached 19.4 g/L, with a sevenfold increase and a yield of 7.3% (g/g-glucose). Using xylose as a carbon source further improved the yield to 9.5% (g/g-xylose). As <span>d</span>-ribulose is synthesized via the pentose phosphate pathway, we metabolically engineered <i>S. lividans</i> to produce the sunscreen metabolite shinorine, which is synthesized from <span>d</span>-sedoheptulose 7-phosphate in the pentose phosphate pathway. Shinorine production was maximized at 34 °C, reaching 762 mg/L, an 11-fold increase compared to that at 28 °C.</p><h3>Conclusions</h3><p>This study reveals that <i>S. lividans</i> exhibits enhanced glucose consumption and metabolite production at elevated temperatures, even under conditions of extensive cell death. We identified <i>S. lividans</i> as a novel producer of the rare sugar <span>d</span>-ribulose and successfully engineered it for high-level shinorine production under elevated temperature conditions. These findings highlight the potential of <i>S. lividans</i> as a promising host for the production of primary and secondary metabolites derived from the pentose phosphate pathway.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"19 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2026-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1186/s13068-026-02758-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147476581","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ethanol perturbs cell wall and membrane homeostasis in Wickerhamomyces anomalus","authors":"Xiaozhu Liu,&nbsp;Yujie Wang,&nbsp;Maogui Wang,&nbsp;Zhengcheng Kuang,&nbsp;Xun Gong,&nbsp;Xuewen Zhang,&nbsp;Yinfeng Li","doi":"10.1186/s13068-026-02756-4","DOIUrl":"10.1186/s13068-026-02756-4","url":null,"abstract":"<div><h3>Background</h3><p><i>Wickerhamomyces anomalus</i>, a flavor-modulating non-<i>Saccharomyces</i> yeast, has garnered significant interest for its remarkable ability to shape wine flavor profiles. However, during fermentation, yeast cells are inevitably exposed to ethanol stress. The specific structural consequences of this stress, particularly its impact on cell wall and membrane homeostasis, remain unclear.</p><h3>Results</h3><p>In this study, we investigated the effects of ethanol stress on the cellular integrity of <i>W. anomalus</i> through a physiological analysis focused on the cell wall and membrane. Our results demonstrated that ethanol stress induced significant morphological and ultrastructural alterations, which were primarily attributed to the disruption of cellular homeostasis. Specifically, ethanol stress compromised cell wall integrity, activated the cell wall integrity (CWI) pathway, and increased the intracellular levels of β-glucan and chitin. Furthermore, ethanol stress disrupted membrane homeostasis by remodeling its composition, reducing integrity and fluidity, while increasing permeability and simultaneously enhancing ATPase activity and elevated intracellular K⁺ levels. Fatty acid profiling also demonstrated a decrease in the monounsaturated fatty acid C18:1 and an increase in very long-chain fatty acids (VLCFAs; C22:0 and C24:0) under ethanol challenge. Exogenous supplementation of these fatty acids was shown to enhance the ethanol stress tolerance of <i>W. anomalus</i>.</p><h3>Conclusions</h3><p>These findings provide crucial insights into the mechanistic basis of ethanol stress response in <i>W. anomalus</i> and offer a foundation for developing novel strategies to improve its industrial utilization under fermentative stress conditions.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"19 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2026-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1186/s13068-026-02756-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147446302","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Smart-driven bioengineering techniques for enhancing microalgal biohydrogen production","authors":"Zhongliang Sun,&nbsp;Shoukai Guo,&nbsp;Adamu Yunusa Ugya,&nbsp;Weixian Cheng,&nbsp;Yu Zhang,&nbsp;Liqin Sun","doi":"10.1186/s13068-026-02754-6","DOIUrl":"10.1186/s13068-026-02754-6","url":null,"abstract":"<div><p>Microalgae have the potential to produce hydrogen through photosynthesis, making them a promising alternative to traditional fossil fuels. Although the progress in large-scale production is limited by biological constraints, such as low hydrogen production rates and sensitivity to environmental conditions, the bioengineering of microalgae is an important tool that will help overcome these limitations by enhancing hydrogen production efficiency and improving tolerance to varying environmental conditions. The review indicates the effectiveness of the inhibition of photosystem II (PSII), the introduction of oxygen-tolerant hydrogenase variants, and enhanced electron flow to hydrogenase enzymes as effective strategies to improve hydrogen production in microalgae. The role of integrated systems that combine hydrogen production with co-product generation, such as biofuels, bioplastics, or high-value metabolites, will enhance economic feasibility and sustainability. Also, advancements in bioreactor designs, coupled with real-time monitoring and control systems, create optimized environments that favor large-scale production. This integrated bioengineering approach not only maximizes biohydrogen potential, but also aligns with circular bioeconomy principles by minimizing waste and utilizing resources efficiently. Exploring new ways to enhance the integration of the use of microalgae for biohydrogen production and other valuable products will drive a more efficient and environmentally friendly bioprocess.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"19 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2026-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13085277/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147391864","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synechocystis sp. PCC 6803 with ddh disruption and heterologous pk gene expression in the phosphoketolase pathway drives carbon flux toward polyhydroxybutyrate production","authors":"Vetaka Tharasirivat,&nbsp;Xufeng Liu,&nbsp;Peter Lindblad,&nbsp;Saowarath Jantaro","doi":"10.1186/s13068-026-02752-8","DOIUrl":"10.1186/s13068-026-02752-8","url":null,"abstract":"<div><h3>Background</h3><p>To overcome the limitations in the production of polyhydroxybutyrate (PHB) in cyanobacteria, we genetically modified <i>Synechocystis</i> sp. PCC 6803 focusing on carbon metabolism at the phosphoketolase pathway. In addition, for the baseline of the control strain (Ct), an inhibition of the pyruvate-to-lactate reaction was created by the disruption of the native <i>ddh</i> gene that encodes lactate dehydrogenase.</p><h3>Results</h3><p>The effects on cell growth of phosphoketolase (<i>pk</i>) gene expression derived from <i>Pseudomonas aeruginosa</i> ATCC 15442 (Ct_OX<i>pkPa</i>), <i>Bifidobacterium breve</i> strain 203 (Ct_OX<i>pkBb</i>), and <i>Bifidobacterium adolescentis</i> ATCC 15703 (Ct_OX<i>pkBa</i>) were comparable to that observed in the Ct strain. Notably, the PHB production in the Ct_OX<i>pkBb</i> strain increased under the normal growth condition without any stress, reaching 32.5% of dry cell weight. Combined nitrogen and phosphorus deprivation, the Ct_OX<i>pkBb</i> strain significantly accumulated PHB up to 62.2% of dry cell weight within 7 days of treatment. Compared with the Ct strain, the Ct_OX<i>pkBb</i> strain also exhibited a significant reduction in glycogen, in accordance with decreased <i>glgC</i> transcript levels for glycogen synthesis and increased <i>glgX</i> transcript levels for glycogen degradation. Furthermore, under the NP-deprived condition, the Ct_OX<i>pkBb</i> strain exhibited reduced transcript levels of acetate metabolism genes, in particular <i>ackA</i> and <i>acs</i>, compared with the control condition.</p><h3>Conclusions</h3><p><i>Synechocystis</i> PCC 6803 expressing <i>pk</i> from <i>Bifidobacterium breve</i> strain 203 resulted in significant production of PHB, indicating its potential for biotechnological applications.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"19 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2026-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1186/s13068-026-02752-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147367682","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluating isoprenol production using the IPP-bypass pathway in the oleaginous yeast Rhodosporidium toruloides","authors":"Valentina E. Garcia,&nbsp;Gina M. Geiselman,&nbsp;Hee Jin Hwang,&nbsp;Yan Chen,&nbsp;Jennifer W. Gin,&nbsp;Jack McFadden-Mitchell,&nbsp;Veronica Montgomery,&nbsp;Ramu Kakumanu,&nbsp;Shubhasish Goswami,&nbsp;Joshua McCauley,&nbsp;Paul A. Adamczyk,&nbsp;Edward E. K. Baidoo,&nbsp;Christopher J. Petzold,&nbsp;Blake A. Simmons,&nbsp;Taek Soon Lee,&nbsp;John M. Gladden","doi":"10.1186/s13068-026-02750-w","DOIUrl":"10.1186/s13068-026-02750-w","url":null,"abstract":"<div><h3>Background</h3><p>To strengthen the national energy supply, there is an increasing demand for domestically generated aviation fuels. Bio-derived advanced aviation fuels offer the opportunity to meet this domestic need while presenting a unique opportunity to investigate the production of novel aviation fuels. Isoprenol, a chemical precursor to such novel fuels, has been shown to be a biologically producible compound in model organisms, but its bio-producibility needs to be further explored in organisms more compatible with industrial bioproduction.</p><h3>Results</h3><p>In this work, we evaluate isoprenol production using the promising bioproduction yeast, <i>Rhodosporidium toruloides</i>. First, we show successful isoprenol production using the IPP-bypass pathways most successful in laboratory strains of <i>E. coli</i> and <i>S. cerevisiae</i>. Next, we demonstrate that increased flux through the mevalonate pathway only modestly increases isoprenol titers. Using proteomics, we identified a potential bottleneck in production at the final step in the IPP-bypass pathway and explored alternative enzymes for this step. Finally, the top three strains of <i>R. toruloides</i> were evaluated in sorghum hydrolysates generated using cholinium lysinate. Through this work, 93.1 mg/L of isoprenol was produced in mock medium and 27.3 mg/L in sorghum hydrolysates.</p><h3>Conclusion</h3><p>Together these results lay the foundation for future work for the production of isoprenol from bioproduction crops.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"19 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2026-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1186/s13068-026-02750-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147349960","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Process optimization and transcriptomic profiling reveal an inverse relationship between gene expression and succinic acid production from sugarcane leaves","authors":"Napapat Sitthikitpanya,&nbsp;Nantharat Wongfaed,&nbsp;Sureewan Sittijunda,&nbsp;Sompong O-Thong,&nbsp;Prawit Kongjan,&nbsp;Rattana Jariyaboon,&nbsp;Pensri Plangklang,&nbsp;Alissara Reungsang","doi":"10.1186/s13068-026-02751-9","DOIUrl":"10.1186/s13068-026-02751-9","url":null,"abstract":"<div><p>Succinic acid is a valuable platform chemical widely used in the food, pharmaceutical, and bioplastics industries. This study combines process optimization with transcriptomic analysis to investigate succinic acid production from sugarcane leaf hydrolysate (SLH) using <i>Actinobacillus succinogenes</i> TISTR 1994 and to gain insight into the molecular mechanism underlying succinate biosynthesis from SLH-derived sugars. Systematic optimization identified MgCO₃ concentration, sugar concentration, and initial pH as key factors influencing succinic acid production. Under optimal conditions (52.84 g/L MgCO₃, 49.68 g/L sugar, pH 7.94), succinic acid production reached 18.87 ± 0.42 g/L with a yield of 0.59 g/g, productivity of 0.39 g/L/h, and 95.3% sugar utilization efficiency, compared to 76.0% under non-optimized conditions. Genome-wide transcriptomic analysis revealed 1075 differentially expressed genes during mid-exponential phase. Notably, non-optimized conditions exhibited higher expression of key reductive tricarboxylic acid (TCA) cycle genes, including malate dehydrogenase (4.84-fold), fumarate reductase (2.00-fold), and phosphoenolpyruvate carboxykinase (1.55-fold), yet resulted in lower succinate titers. This inverse correlation between transcript levels and metabolic output suggests that environmental factors may influence fermentation performance potentially through mechanisms beyond transcription alone. Instead, optimized environmental conditions—particularly MgCO₃ concentration and pH—appeared to support succinate biosynthesis by providing favorable biochemical conditions, including pH stability for enzyme function and sufficient CO₂/HCO₃⁻ availability for carboxylation reactions. These findings suggest that process optimization influences succinic acid production from lignocellulosic biomass and that transcript levels alone may be insufficient predictors of fermentation performance, pointing to a potential contribution of post-transcriptional regulation.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"19 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2026-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13037298/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147277762","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Innovative mycosynthesis of chitosan nanoparticles via bionanofactory Penicillium crustosum: optimization, characterization, and application against building-deteriorating fungus, Trichosporon asahii","authors":"Hadeel El-Shall,&nbsp;Noura El-Ahmady El-Naggar,&nbsp;Shaimaa Elyamny,&nbsp;Asmaa A. El-Sawah,&nbsp;Marwa Eltarahony","doi":"10.1186/s13068-025-02734-2","DOIUrl":"10.1186/s13068-025-02734-2","url":null,"abstract":"<div><p>Biocorrosion of building materials is a global challenge that threatens both modern buildings and cultural heritage. This degradation is largely driven by interactions between microbes, particularly fungi, and various gaseous effluents containing nitrogenous, sulfurous, and carbonaceous aerosols from anthropogenic activities, leading to progressive biocorrosion of construction surfaces. Therefore, this study aims to reduce such detrimental effects using chitosan nanoparticles (CNPs). An eco-friendly biosynthesis approach was employed, using the cell-free supernatant of <i>Penicillium</i> sp. strain HNSAM-7 to produce the CNPs. This strain has been identified as <i>Penicillium crustosum</i> strain HNSAM-7 according to the analysis of ITS region sequence, together with its morphological characteristics. The physicochemical properties of CNPs were characterized; SEM and TEM analyses revealed that the biosynthesized CNPs resemble spheres, have a smooth surface, and varied in size, with an average size of 26.19 nm. The X-ray diffraction demonstrates the crystalline nature of CNPs. The FTIR analysis detected multiple functional groups involving O–H, -NH₂, CH, CH₂, CONH₂, C–O, C–OH, C–O–C, –C≡CH, O = S = O, NH, C − O groups. CNPs have a surface with a positive charge, with a Zeta potential value of + 26.2 mV. Consequently, FCCCD was used to maximize CNPs’ production, achieving a maximum yield of 10.71 mg/mL under conditions of 1.19% (w/v) chitosan concentration, initial pH 4.99, and 99.94% (v/v) cell-free supernatant. The fungicidal activity of CNPs was evaluated in vitro against <i>Trichosporon asahii</i> using a killing-time assay. Higher concentrations of CNPs (250 and 500 µg/mL) demonstrated significant fungicidal activity. SEM analysis revealed substantial spore and mycelium structural damage, including disruption of biofilm architecture. These findings suggest that eco-friendly, biosynthesized CNPs have potential as possible bio-safe coatings for the protection of building structures against microbial corrosion.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"19 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2026-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12930960/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146230055","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}